Evaporator unit



A ril 26, 1949. 'w. F. CCOLEY EYAPORATQR UNIT Filed May 20, 1946 lA/VE/VTOI? WILLIAM F. COOLEY ATTOR y Patented Apr. 26, 1949 1 I 1 UNITED STATES PATENT OFFICE 2 Claims.

The present invention relates to improvements in an evaporator unit, and its principal object is to provide a fan-operated evaporator unit used in connection with a refrigerating system, and adapted particularly for larger systems in which an entire room is to be cooled, although the principle of the invention may be applied to smaller units.

More particularly, it is proposed to provide a housing for an evaporator unit Consisting of three preferably alined sections, a rectangular front section in which the heat-exchange portions of an evaporator coil are mounted, a cylindrical rear section in which the fan is mounted and a transition section being streamlined and shaped to smoothly merge into the outlines of the other two sections.

It is further proposed to provide a forced draft evaporator unit in which the exposed portions of the evaporator tube lie directly in the path of the forced draft and in which the forced draft is evenly distributed over the entire tube-occupied area to prevent uneven frosting and intensified frosting at the four corners of the tubeoccupied area.

It is still further proposed to provide an evaporator unit of the character described in which the exposed tube portions subject to the draft are grouped in multiple series and are bunched in a comparatively small area, whereby a certain amount of pressure is built up in the transition piece between the fan and the tubes for a more effective heat exchange.

And finally, it is proposed to provide an evaporator unit in which all the exposed portions of the evaporator tubes are arranged in one location which allows a comparatively small drip pan to receive products of any defrosting process which may take place.

Further objects and advantages of my invention will appear as the specification proceeds, and the new and useful features of the same will be fully defined in the claims hereto appended.

The preferred form of the invention is illustrated in the accompanying drawing, forming part of this application, in which:

Figure 1 shows a side elevation of my evaporator unit, a portion being shown in section;

Figure 2, a front view of the same;

Figure 3, a cross-section taken along line 33 of Figure 1; and

Figure 4, a cross-section taken along line 4-4 of Figure 1.

While I have shown only the preferred form of my invention, it should be understood that varione changes or modifications may be made within the scope of the claims hereto attached, without departing from the spirit of the invention.

Referring to the drawing in detail, the housing i of my evaporator unit is made in three sections, 2, 3 and 4 mounted in axial alinement with one another.

The section 2 is made in the form of a short, rectangular shell comprising a bottom plate 5, side plates 5 and a top plate I. The side plates 6 are formed with inwardly turned flanges 8 along the front edges thereof to present face plates and with similar inwardly turned flanges 9 along the rear edges thereof, the inner edges of the front and rear flanges being interconnected by sus-' taining walls Ill.

The walls In thus form, with the top and bottom plates, a rectangular shell opening which constitutes the effective draft opening of the front section.

A drip pan H is suspended from the front section, and the bottom plate 5 is suitably apertured to all-ow drippings to drip into the pan.

The evaporator coil I2 is mounted in the front section and comprises a plurality of parallel horizontal tubes I2 positioned across the front section opening. The tubes are supported in the sustaining walls l0, and are connected, outside the sustaining walls, by suitable U-shaped joints l 3 arranged in such a manner as to make the coil continuous.

The evaporator coil, for the purposes of the present invention, may be of any suitable form to facilitate rapid heat exchange, but is preferably made as described in my co-pendin application, Serial Number 646,670, filed February 9, 1946.

In the co-pending application, each exposed tube has a hollow streamlined shell structure l4 mounted thereon, the shell structure being revolvable on the tubes and being adapted to act as shutters for closing the frame opening, when moved into vertical position. The shell structures are mounted for operation by a common operating rod (not shown) The tubes are mounted in spaced relation to one another and in such a manner as to substantially cover the entire area of the opening of the front section 2. They may be arranged in several vertical series, as shown, the :tubes of one series being preferably staggered with respect to those of the other, as shown.

The rear section 4 of the housing is made cylindrical, preferably with an outward flare l5, to .produce a certain Venturi eifect. A fan l6 is mounted in this section and is operated by a suitably disposed motor IT.

The two sections 2 and 4 are interconnected by a transition piece identified as section 3, which is formed to merge, at its rear end, into the cylindrical rear section, and at its front end into the opening edge of the rectangular front section.

For thispurpose the rear edge of the transition piece ismade cylindrical and the front edge is made rectangular in shape, while the body portion is constructed so as to gradually merge or streamline from one shape into the other.

In operation, the fan is set to blow air through the three sections toward the evaporator coil. Since the numerous coil sections in the front section of the housing limit the space of exit, a certain pressure will be built up in the intermediate portions of the housing, and the shape of the transition piece will distribute the draft overthe entire area of the front section opening,thereby eliminating dead corners and frost formation on the tubes at the corners of the opening.

The single draft feature of my invention allows all of the coil tubes to be congregated in a comparatively small area, thereby intensifying the heatexchange and leaving only a small space for drippings, thus allowing a comparatively small drip pan to take care of the latter.

The air being driven in one direction only, that is, axially with respect to the fan, there will be no eddy currents, no deflection of air, except such as is incident to the heat exchange, which makes for greater efiiciency of the fan and more effective heat exchange.

A single motor and a single fan will take care of :the device. The draft is uniformly distributed over the effective-coil area, and there is no back draft through the fan.

The housing may be suitably suspended from the ceiling or attached to the Wall in any place selected for most effective "circulation through the room to be refrigerated.

Iclai'm:

1. An evaporator unit comprising a housing having, a rectangular front section with parallel side walls :and parallel top and bottom walls, a cylindrical rear section having a diameter equal to the spacing between the top and bottom walls, and a transition section connecting the former sections, the transition section having a cylindrical rear end matching the rear section, a rectangular front end registering with the front section and :a body streamlined and shaped to smoothly merge from the cylindrical form at one end into the rectangular form at the other end, an evaporator coil having tubes mounted across the front section, and a fan mounted in the rear section.

2. An evaporator unit comprising a housing having, a rectangular front section with parallel side walls and parallel top and bottom walls, a cylindrical rear section having a diameter equal to the spacing between the top .and bottom walls, and a'transition section connecting the former sections, the transition section having a cylindrical rear end matching the rearsection, 9, rectangular front end registering with the front section and a body streamlined and shaped to smoothly merge from the cylindrical form at one end into the rectangular form at the other end, and the transition section being longer than the combined lengths of the front-end rear sections, an evaporator coil having tubes mounted across the front section, and a fan mounted in the rear section.

'WILLIAM F. COOLEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name l ate 374,094 Smith ,i-rov. 29, 1887 1,975,066 Sanders-on Sept. 25, 1934 2,105,692 Huniche Jan. 18, 1938 2,330,026 Clarke JUIYIO, 1945 

